Electric-arc lamp.



PATENTED NOV. 3, 1903.

H. BREMER.

ELECTRIC ARC LAMP.

APPLIOATION FILED MAY 2, 1901.

2 SHHETSSHBET 1.

N0 MODEL.

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PATENTED NOV. 3, 1903.

H. BREMBR.

ELECTRIC ARC LAMP.

APPLIUATION FILED my 2, 1901.

2 SHEETS-SHEET 2.

110 IODEL.

m: norms PETERS c0. PHOl'O-L\THO,WASH

i atented November 3, 1903.

UNITED STATES PATENT OFFICE.

HUGO BREMER, OF NEI-IEIM, GERMANY.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 743,238, dated November 3, 1903.

Application filed May 2, 1901. Serial No. 58,534. (No model.)

To aZZ whom it may concern:

Be it known that I, HUGO BREMER, a subject of the Emperor of Germany, residing at Neheim, in the Province of Westphalia, German y-,have invented new and useful Improvements in Arc-Lamps, of which the following is a full and clear specification, such as will enable others skilled in the art of this manufacture to make and use the same.

The present invention relates to devices for feeding the electrodes of an arc-lamp when such electrodes are downwardly pointed and either parallel or convergent.

It also relates to special means for striking the arc in a lamp of the character described.

The invention is illustrated in the accompanying drawings, in which'- Figure 1 is a diagram of a lamp, showing means for releasing the carbons separately. Fig. 2 illustrates a modification; and Figs. 3, 4, 5, 6, 7, 8, 9, and 10 illustrate various means for establishing the are between electrodepoints.

In Fig. 1 the carbons or electrodes are shown at 1 and 2. Cooperating with each of the electrodes is a finger d, operated intermittently by a suitable clockwork mechanism a in such a manner as to be brought into contact each with the lateral surface of its own electrode. When the combustion has progressed so far that the finger (1 instead of meeting the straight vertical side of its electrode strikes against an inclined surface or even moves underneath the end of the electrode, as shown in dotted lines in Fig. 1, it operates to close a circuit through one or the other of the electromagnets 3 and 4:, whereby the said magnet is energized and caused to attract its armature e. The said armature is centrally pivoted and is connected at each end with a releasing device f, consisting of an angular lever 5, pivoted at 6. The inner end of the lever presses against one of the electrodes passing through an opening in one of the carbonholders 7 7. Then one of the electromagnets 3 and i is energized in the manner already described, it operates to release the electrode with which the finger d has made contact and allows it to feed.

In place of the clockwork I may use any kind of motor for producing intermittent contact between one of the fingers and its appropriate electrode.

In Fig. 5 the finger d is provided with an adjustable contact g, arranged in proximity to a stationary contact 8. When the carbon burns away and the finger passes beneath its lower end, contact is made between the terminals g and 8, whereupon an electromagnet h is energized and releases a toothed or friction wheel 11, maintaining such release until the descending carbon has forced the finger 01 back into its normal position or until the carbon has been advanced by some other means.

With carbons pointing downward the arc is frequently formed by placing a piece of metal against the ends of the carbons. It has been found that the mechanical arrangements for effecting this and the formation of charred particles by the carbons cause difficulties, and also, owing to the fact that at the points of contact between the said piece of metal Z andlthe carbons small arcs are formed both at the negative and the positive pole, Figs. 3 and 4:, there is difliculty in getting the arcs to coalesce, since by reason of the opposite directions of their currents they repel each other, Fig. 8. Consequently the arcs are Very easily broken, the repulsion occurring as soon as two arcs are formed, because with the carbons pointing downward the magnetic field formed by the current itself has a downward or outward spreading tendency. This is, however, principally the case when, as is most usual with these lamps, a special magnetic field is used to increase said tendency. The greatest part of the infiuence of the magnetic field injurious to the formation of the arc can be removed by interrupting the current producing the said special magnetic field while the arc is being formed or by producing while the latter is taking place another magnetic field which neutralizes the before-mentioned outward tendency or converts it into the opposite, so that the arcs both curve inward, and thus have a tendency to combine to form one are. For this purpose a stationary magnet is may be used, as shown in Fig. 6.

A suitable method of preventing the effects of the two arcs upon each other is to effect ICO rod both do not make contact.

the formation of the arc in the manner represented in Figs. 7 and 8.

The arc-forming device or rod in is pivoted under spring-pressure to an oscillating lever 71 and is moved from the side to a position beneath the two carbons in such a manner that at first it forms one are 00 with one of the car bons and bears against the other carbon, so that it only forms a very short are. 'On the device then being moved away the are m is carried over to the second carbon, as shown in Fig. 8, and on its being moved away still farther the direct connection of the arc with the said second carbon is effected, as experiments have completely proved.

Preferably the arc-forming rod should first make contact with the positive carbon and form an arc with the same receiving negative current by contact with the negative carbon. In this manner the destruction of the areforming rod is made as small as possible, the more so since duringits friction with the negative carbon particles of the latter adhere to its surface and during the formation of the are only these particles actually form the arc, so that the rod m is very slightly attacked or not at all.

The arrangement of the arc-forming rod under spring action must be such that during its withdrawal from the positive carbon it continues to bear against the negative carbon, so that only one are is formed all the time.

With the system of forming the are described it sometimes occurs that when the two carbons strike against the arc-forming In this case it is sufficient if said rod makes contact with the carbon connected with the opposite pole, Fig. 9. An arc is then first formed between this carbon and the rod, which are passes very easily over to the carbon not yet burning, since the carbon itself offers a convenient means for the reception of the current, and the arc is thus formed even if the rod does not come into contact with both carbons.

The arrangement is particularly suitable where the arc-forming rod is moved against the carbon by means of a magnet. Short circuit between the two carbons is then made on the contact of the said rod with the carbon, and this short circuit causes the immediate withdrawal of the rod and the interruption of the current, and thus a powerful flash of the are. On this flash follows the renewed formation of the are, so that a continued forcircuit is thus produced, which results in the immediate removal of the arc-forming rod. This connection with a pole thus results in much more rapid withdrawal of the areforming rod and in reduced intervals between the flashes during the formation of the arc. Another advantage is obtained in lamps in which the carbons generally produce charred particles, which frequently interfere with the making of contact by the arc-forming rod. As the result is not materially reduced if only the positive electrode contains admixtures having that effect, it is then sufficient to connect the arc-forming device with the positive pole in the same manner as the carbon forming said charred particles. Between the arc-forming device and the negative carbon, which is always clean, and thus insures contact, the continuous spark formation hereinbefore referred to is thus produced, and the latter softens the charred particles which prevent contact or produces the are, even if the said particles at the edges of the carbon project below the clean point thereof, and entirely prevent conductive contact between the arc-forming device and the said point.

Experiments show that the flash formed be tween the arc-forming rod and the negative carbon, so to say, penetrates the rim of charred carbon and produces direct connection with the positive carbon. The flash used for forming the arc can also be produced between two entirely separate arc-forming points, as shown in Fig. 10, which are brought into contact with each other and are then drawn apart, whereupon an arc is formed. This are rises to the carbons above it, so that an arc is formed between the carbon-points, whereupon the two arc-forming points are withdrawn.

I claim as my invention- 1. In an electric-arc lamp, the combination of a pair of downwardly-pointed parallel or converging carbons, feeding mechanism holding said carbons normally suspended, electromagnetic means in a normally open circuit for controlling the mechanism, and a circuitclosing lever whose action is related to the rate of carbon consumption for controlling the normally open circuit.

2. In an electric-arc lamp, the combination of a pair of downwardly-pointed parallel or converging carbons, feeding mechanism holding said carbons normally suspended, electromagnetic means in a normally open circuit for controlling the feeding mechanism, and a circuit closing lever normally pressing against one of the carbons, the said lever being adapted to close the normally open circuit when it passes under the end of the burned-away electrode.

3. In an electric-arc lamp, the combination of a pair of downwardly-pointed parallel or converging carbons, separate feeding mechanism holding each carbon normally suspended, electromagnetic devices in normally open circuits for controlling each feeding mechanism, and a circuit-closing lever for each circuit, the said lever being adapted to close its own circuit when its appropriate carbon has burned away to a predetermined point.

4. In an electric-arc lamp, the combination with a pair of downwardly-pointed parallel or converging carbons, of an arc-striking device, consisting of two separate conducting rods or parts, means for bringing each of the 10 said rods into contact with a diiferent electrode, and means for Withdrawing the said rods when the lamp-circuit is closed, so as to establish the are, as described.

HUGO BREMER. Witnesses:

HENRY HASPER, WOLDEMAR HAUPT. 

